The script of the language is very old, making it hard to read. It has 12 consonants, 18 vowels, and the āytamஃ, which is neither a consonant nor a vowel. The āytam can be used with other letters to represent sounds not in the Tamil script, such as 'f'. The consonants and vowels can mix to form compound letters. Altogether, there are 247 sounds/sets of sounds in the Tamil script. Tamil, like English, is written from left to right.

It has been said that most of the other Indian scripts are basically derived from the letters of Tamil. In a few cases, the words themselves were used in other Indian languages for better understanding. Tamil numbers have certainly shaped the numbers in other Dravidian language family.